Glitch

// width - image width
// height - image height

// input - two-dimentional array of RGBA pixels of original image
// output - two-dimentional array of RGBA pixels of processed image
// Both are initialized with the same image

// channel - R, G, or B channel to copy (shifted) in output image
// copyChannelPoint(x, y) - pseudopoint, specifying where to place (top left corener) shifted channel data from on output image
// copyPixelsData - pseudostrust, specifying areas of input image to be copied (shifted) to output:
// y - top coord f the rect to copy (x == 0)
// height - height of the rect to copy (width == 780)
// shiftX - left coord of the point to place rect to (use y for top), all the pixels that shifts out of the limits will wrap to the opposite end of the row
// Number of copyPixelsData may vary.

function glitch(channel, copyChannelPoint.x, copyChannelPoint.y, [copyPixelsData0.y, copyPixelsData0.height, copyPixelsData0.shiftX, copyPixelsData1.y, copyPixelsData1.height, copyPixelsData1.shiftX...] ) {
    // copy whole pixels from rectangular areas of input image to output one, shifted coords		
    for (var i = 0; i < copyPixelsData.length; i++) {
        shiftRectWidth = width - Math.abs(copyPixelsData[i].shiftX);
        wrapRectWidth = width - rectWidth;

        if(copyPixelsData[i].shiftX > 0) {        
            copyPixels(input, output, new Rectangle(0, copyPixelsData[i].y, shiftRectWidth, copyPixelsData[i].height), new Point(wrapRectWidth, copyPixelsData[i].y));
            copyPixels(input, output, new Rectangle(shiftRectWidth, copyPixelsData[i].y, wrapRectWidth, copyPixelsData[i].height), new Point(0, copyPixelsData[i].y));
        } else {
            copyPixels(input, output, new Rectangle(wrapRectWidth, copyPixelsData[i].y, shiftRectWidth, copyPixelsData[i].height), new Point(0, copyPixelsData[i].y));
            copyPixels(input, output, new Rectangle(0, copyPixelsData[i].y, wrapRectWidth, copyPixelsData[i].height), new Point(shiftRectWidth, copyPixelsData[i].y));
        }
        
        copyPixels(input, output, new Rectangle(x, copyPixelsData[i].y, width, copyPixelsData[i].height), new Point(copyPixelsData0.shiftX, copyPixelsData[i].y));
    }
    
    // copy single channel data from rectangular areas of input image to output one, shifted coords
    copyChannel(input, output, new Rectangle(0, 0, 780, 780), new Point(copyChannelPoint.x, copyChannelPoint.y), channel, channel);
}

function copyPixels(source, dest, sourceRect, destPoint) {
    processRect(source, dest, sourceRect, destPoint, function(dx, dy, rgba) {
        dest[dy][dx] = {r: rgba.r, g: rgba.g, b: rgba.b, a: rgba.a};
    });
}

function copyChannel(source, dest, sourceRect, destPoint, sourceChannel, destChannel) {
    processRect(source, dest, sourceRect, destPoint, function(dx, dy, rgba) {
        dest[dy][dx][destChannel] = rgba[sourceChannel];
    });
}

function processRect(source, dest, sourceRect, destPoint, routine) {
    var sx, sy, dx, dy, rgba;
    for (var y = 0; y < sourceRect.height; y++) {
        for (var x = 0; x < sourceRect.width; x++) {
            dx = destPoint.x + x;
            dy = destPoint.y + y;
            sx = sourceRect.x + x;
            sy = sourceRect.y + y;

            routine(dx, dy, source[sy][sx]);
        }
    }
}